When you install custom ROMs on the AT&T Galaxy S3 SGH-I717, you might have to manually set your APN and 4G LTE PTA settings, here’s the settings you need:
For 4G LTE PTA/HSPA+:
MMS Proxy: proxy.mobile.att.net
MMS port: 80
APN type: default,mms,supl,hipri
MMS Proxy: wireless.cingular.com
MMS Port: 80
APN type: default,supl,mms
You can also use this method to switch between HSPA+ or 4G LTE on your phone to save battery life.Need Help? Best way to reach me is on Twitter for the fastest response!
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You will need a rooted Galaxy S3 to install all ROM/kernels.
NOTE: PLEASE ONLY INSTALL ROMS INTENDED FOR YOUR VERSION OF GALAXY S3! Otherwise you WILL BRICK YOUR PHONE and I will not be responsible!
First time to rooting and custom ROMs? Please see our Galaxy S3 Root FAQ FIRST! Note: T-Mobile Galaxy S3 ROMs are compatible with Canadian Wind, Mobilicity, and Videotron Galaxy S3s.
AT&T Galaxy S3 ROMs are compatible with Canadian Bell, Telus, and Sasktel Galaxy S3s.